xref: /freebsd/sys/arm/freescale/imx/imx6_anatop.c (revision 788ca347b816afd83b2885e0c79aeeb88649b2ab)
1 /*-
2  * Copyright (c) 2013 Ian Lepore <ian@freebsd.org>
3  * Copyright (c) 2014 Steven Lawrance <stl@koffein.net>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 /*
32  * Analog PLL and power regulator driver for Freescale i.MX6 family of SoCs.
33  * Also, temperature montoring and cpu frequency control.  It was Freescale who
34  * kitchen-sinked this device, not us. :)
35  *
36  * We don't really do anything with analog PLLs, but the registers for
37  * controlling them belong to the same block as the power regulator registers.
38  * Since the newbus hierarchy makes it hard for anyone other than us to get at
39  * them, we just export a couple public functions to allow the imx6 CCM clock
40  * driver to read and write those registers.
41  *
42  * We also don't do anything about power regulation yet, but when the need
43  * arises, this would be the place for that code to live.
44  *
45  * I have no idea where the "anatop" name comes from.  It's in the standard DTS
46  * source describing i.MX6 SoCs, and in the linux and u-boot code which comes
47  * from Freescale, but it's not in the SoC manual.
48  *
49  * Note that temperature values throughout this code are handled in two types of
50  * units.  Items with '_cnt' in the name use the hardware temperature count
51  * units (higher counts are lower temperatures).  Items with '_val' in the name
52  * are deci-Celcius, which are converted to/from deci-Kelvins in the sysctl
53  * handlers (dK is the standard unit for temperature in sysctl).
54  */
55 
56 #include <sys/param.h>
57 #include <sys/systm.h>
58 #include <sys/callout.h>
59 #include <sys/kernel.h>
60 #include <sys/limits.h>
61 #include <sys/sysctl.h>
62 #include <sys/module.h>
63 #include <sys/bus.h>
64 #include <sys/rman.h>
65 
66 #include <dev/ofw/ofw_bus.h>
67 #include <dev/ofw/ofw_bus_subr.h>
68 
69 #include <machine/bus.h>
70 
71 #include <arm/arm/mpcore_timervar.h>
72 #include <arm/freescale/fsl_ocotpreg.h>
73 #include <arm/freescale/fsl_ocotpvar.h>
74 #include <arm/freescale/imx/imx6_anatopreg.h>
75 #include <arm/freescale/imx/imx6_anatopvar.h>
76 
77 static SYSCTL_NODE(_hw, OID_AUTO, imx6, CTLFLAG_RW, NULL, "i.MX6 container");
78 
79 static struct resource_spec imx6_anatop_spec[] = {
80 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
81 	{ SYS_RES_IRQ,		0,	RF_ACTIVE },
82 	{ -1, 0 }
83 };
84 #define	MEMRES	0
85 #define	IRQRES	1
86 
87 struct imx6_anatop_softc {
88 	device_t	dev;
89 	struct resource	*res[2];
90 	struct intr_config_hook
91 			intr_setup_hook;
92 	uint32_t	cpu_curmhz;
93 	uint32_t	cpu_curmv;
94 	uint32_t	cpu_minmhz;
95 	uint32_t	cpu_minmv;
96 	uint32_t	cpu_maxmhz;
97 	uint32_t	cpu_maxmv;
98 	uint32_t	cpu_maxmhz_hw;
99 	boolean_t	cpu_overclock_enable;
100 	boolean_t	cpu_init_done;
101 	uint32_t	refosc_mhz;
102 	void		*temp_intrhand;
103 	uint32_t	temp_high_val;
104 	uint32_t	temp_high_cnt;
105 	uint32_t	temp_last_cnt;
106 	uint32_t	temp_room_cnt;
107 	struct callout	temp_throttle_callout;
108 	sbintime_t	temp_throttle_delay;
109 	uint32_t	temp_throttle_reset_cnt;
110 	uint32_t	temp_throttle_trigger_cnt;
111 	uint32_t	temp_throttle_val;
112 };
113 
114 static struct imx6_anatop_softc *imx6_anatop_sc;
115 
116 /*
117  * Table of "operating points".
118  * These are combinations of frequency and voltage blessed by Freescale.
119  */
120 static struct oppt {
121 	uint32_t	mhz;
122 	uint32_t	mv;
123 } imx6_oppt_table[] = {
124 /*      { 396,	 925},  XXX: need functional ccm code for this speed */
125 	{ 792,	1150},
126 	{ 852,	1225},
127 	{ 996,	1225},
128 	{1200,	1275},
129 };
130 
131 /*
132  * Table of CPU max frequencies.  This is used to translate the max frequency
133  * value (0-3) from the ocotp CFG3 register into a mhz value that can be looked
134  * up in the operating points table.
135  */
136 static uint32_t imx6_ocotp_mhz_tab[] = {792, 852, 996, 1200};
137 
138 #define	TZ_ZEROC	2732	/* deci-Kelvin <-> deci-Celcius offset. */
139 
140 uint32_t
141 imx6_anatop_read_4(bus_size_t offset)
142 {
143 
144 	KASSERT(imx6_anatop_sc != NULL, ("imx6_anatop_read_4 sc NULL"));
145 
146 	return (bus_read_4(imx6_anatop_sc->res[MEMRES], offset));
147 }
148 
149 void
150 imx6_anatop_write_4(bus_size_t offset, uint32_t value)
151 {
152 
153 	KASSERT(imx6_anatop_sc != NULL, ("imx6_anatop_write_4 sc NULL"));
154 
155 	bus_write_4(imx6_anatop_sc->res[MEMRES], offset, value);
156 }
157 
158 static void
159 vdd_set(struct imx6_anatop_softc *sc, int mv)
160 {
161 	int newtarg, oldtarg;
162 	uint32_t delay, pmureg;
163 	static boolean_t init_done = false;
164 
165 	/*
166 	 * The datasheet says VDD_PU and VDD_SOC must be equal, and VDD_ARM
167 	 * can't be more than 50mV above or 200mV below them.  For now to keep
168 	 * things simple we set all three to the same value.
169 	 */
170 
171 	pmureg = imx6_anatop_read_4(IMX6_ANALOG_PMU_REG_CORE);
172 	oldtarg = pmureg & IMX6_ANALOG_PMU_REG0_TARG_MASK;
173 
174 	/* Convert mV to target value.  Clamp target to valid range. */
175 	if (mv < 725)
176 		newtarg = 0x00;
177 	else if (mv > 1450)
178 		newtarg = 0x1F;
179 	else
180 		newtarg = (mv - 700) / 25;
181 
182 	/*
183 	 * The first time through the 3 voltages might not be equal so use a
184 	 * long conservative delay.  After that we need to delay 3uS for every
185 	 * 25mV step upward.  No need to delay at all when lowering.
186 	 */
187 	if (init_done) {
188 		if (newtarg == oldtarg)
189 			return;
190 		else if (newtarg > oldtarg)
191 			delay = (newtarg - oldtarg) * 3;
192 		else
193 			delay = 0;
194 	} else {
195 		delay = 700 / 25 * 3;
196 		init_done = true;
197 	}
198 
199 	/*
200 	 * Make the change and wait for it to take effect.
201 	 */
202 	pmureg &= ~(IMX6_ANALOG_PMU_REG0_TARG_MASK |
203 	    IMX6_ANALOG_PMU_REG1_TARG_MASK |
204 	    IMX6_ANALOG_PMU_REG2_TARG_MASK);
205 
206 	pmureg |= newtarg << IMX6_ANALOG_PMU_REG0_TARG_SHIFT;
207 	pmureg |= newtarg << IMX6_ANALOG_PMU_REG1_TARG_SHIFT;
208 	pmureg |= newtarg << IMX6_ANALOG_PMU_REG2_TARG_SHIFT;
209 
210 	imx6_anatop_write_4(IMX6_ANALOG_PMU_REG_CORE, pmureg);
211 	DELAY(delay);
212 	sc->cpu_curmv = newtarg * 25 + 700;
213 }
214 
215 static inline uint32_t
216 cpufreq_mhz_from_div(struct imx6_anatop_softc *sc, uint32_t div)
217 {
218 
219 	return (sc->refosc_mhz * (div / 2));
220 }
221 
222 static inline uint32_t
223 cpufreq_mhz_to_div(struct imx6_anatop_softc *sc, uint32_t cpu_mhz)
224 {
225 
226 	return (cpu_mhz / (sc->refosc_mhz / 2));
227 }
228 
229 static inline uint32_t
230 cpufreq_actual_mhz(struct imx6_anatop_softc *sc, uint32_t cpu_mhz)
231 {
232 
233 	return (cpufreq_mhz_from_div(sc, cpufreq_mhz_to_div(sc, cpu_mhz)));
234 }
235 
236 static struct oppt *
237 cpufreq_nearest_oppt(struct imx6_anatop_softc *sc, uint32_t cpu_newmhz)
238 {
239 	int d, diff, i, nearest;
240 
241 	if (cpu_newmhz > sc->cpu_maxmhz_hw && !sc->cpu_overclock_enable)
242 		cpu_newmhz = sc->cpu_maxmhz_hw;
243 
244 	diff = INT_MAX;
245 	nearest = 0;
246 	for (i = 0; i < nitems(imx6_oppt_table); ++i) {
247 		d = abs((int)cpu_newmhz - (int)imx6_oppt_table[i].mhz);
248 		if (diff > d) {
249 			diff = d;
250 			nearest = i;
251 		}
252 	}
253 	return (&imx6_oppt_table[nearest]);
254 }
255 
256 static void
257 cpufreq_set_clock(struct imx6_anatop_softc * sc, struct oppt *op)
258 {
259 	uint32_t timeout, wrk32;
260 
261 	/* If increasing the frequency, we must first increase the voltage. */
262 	if (op->mhz > sc->cpu_curmhz) {
263 		vdd_set(sc, op->mv);
264 	}
265 
266 	/*
267 	 * I can't find a documented procedure for changing the ARM PLL divisor,
268 	 * but some trial and error came up with this:
269 	 *  - Set the bypass clock source to REF_CLK_24M (source #0).
270 	 *  - Set the PLL into bypass mode; cpu should now be running at 24mhz.
271 	 *  - Change the divisor.
272 	 *  - Wait for the LOCK bit to come on; it takes ~50 loop iterations.
273 	 *  - Turn off bypass mode; cpu should now be running at the new speed.
274 	 */
275 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_ARM_CLR,
276 	    IMX6_ANALOG_CCM_PLL_ARM_CLK_SRC_MASK);
277 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_ARM_SET,
278 	    IMX6_ANALOG_CCM_PLL_ARM_BYPASS);
279 
280 	wrk32 = imx6_anatop_read_4(IMX6_ANALOG_CCM_PLL_ARM);
281 	wrk32 &= ~IMX6_ANALOG_CCM_PLL_ARM_DIV_MASK;
282 	wrk32 |= cpufreq_mhz_to_div(sc, op->mhz);
283 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_ARM, wrk32);
284 
285 	timeout = 10000;
286 	while ((imx6_anatop_read_4(IMX6_ANALOG_CCM_PLL_ARM) &
287 	    IMX6_ANALOG_CCM_PLL_ARM_LOCK) == 0)
288 		if (--timeout == 0)
289 			panic("imx6_set_cpu_clock(): PLL never locked");
290 
291 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_ARM_CLR,
292 	    IMX6_ANALOG_CCM_PLL_ARM_BYPASS);
293 
294 	/* If lowering the frequency, it is now safe to lower the voltage. */
295 	if (op->mhz < sc->cpu_curmhz)
296 		vdd_set(sc, op->mv);
297 	sc->cpu_curmhz = op->mhz;
298 
299 	/* Tell the mpcore timer that its frequency has changed. */
300         arm_tmr_change_frequency(
301 	    cpufreq_actual_mhz(sc, sc->cpu_curmhz) * 1000000 / 2);
302 }
303 
304 static int
305 cpufreq_sysctl_minmhz(SYSCTL_HANDLER_ARGS)
306 {
307 	struct imx6_anatop_softc *sc;
308 	struct oppt * op;
309 	uint32_t temp;
310 	int err;
311 
312 	sc = arg1;
313 
314 	temp = sc->cpu_minmhz;
315 	err = sysctl_handle_int(oidp, &temp, 0, req);
316 	if (err != 0 || req->newptr == NULL)
317 		return (err);
318 
319 	op = cpufreq_nearest_oppt(sc, temp);
320 	if (op->mhz > sc->cpu_maxmhz)
321 		return (ERANGE);
322 	else if (op->mhz == sc->cpu_minmhz)
323 		return (0);
324 
325 	/*
326 	 * Value changed, update softc.  If the new min is higher than the
327 	 * current speed, raise the current speed to match.
328 	 */
329 	sc->cpu_minmhz = op->mhz;
330 	if (sc->cpu_minmhz > sc->cpu_curmhz) {
331 		cpufreq_set_clock(sc, op);
332 	}
333 	return (err);
334 }
335 
336 static int
337 cpufreq_sysctl_maxmhz(SYSCTL_HANDLER_ARGS)
338 {
339 	struct imx6_anatop_softc *sc;
340 	struct oppt * op;
341 	uint32_t temp;
342 	int err;
343 
344 	sc = arg1;
345 
346 	temp = sc->cpu_maxmhz;
347 	err = sysctl_handle_int(oidp, &temp, 0, req);
348 	if (err != 0 || req->newptr == NULL)
349 		return (err);
350 
351 	op = cpufreq_nearest_oppt(sc, temp);
352 	if (op->mhz < sc->cpu_minmhz)
353 		return (ERANGE);
354 	else if (op->mhz == sc->cpu_maxmhz)
355 		return (0);
356 
357 	/*
358 	 *  Value changed, update softc and hardware.  The hardware update is
359 	 *  unconditional.  We always try to run at max speed, so any change of
360 	 *  the max means we need to change the current speed too, regardless of
361 	 *  whether it is higher or lower than the old max.
362 	 */
363 	sc->cpu_maxmhz = op->mhz;
364 	cpufreq_set_clock(sc, op);
365 
366 	return (err);
367 }
368 
369 static void
370 cpufreq_initialize(struct imx6_anatop_softc *sc)
371 {
372 	uint32_t cfg3speed;
373 	struct oppt * op;
374 
375 	SYSCTL_ADD_INT(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx6),
376 	    OID_AUTO, "cpu_mhz", CTLFLAG_RD, &sc->cpu_curmhz, 0,
377 	    "CPU frequency");
378 
379 	SYSCTL_ADD_PROC(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx6),
380 	    OID_AUTO, "cpu_minmhz", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
381 	    sc, 0, cpufreq_sysctl_minmhz, "IU", "Minimum CPU frequency");
382 
383 	SYSCTL_ADD_PROC(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx6),
384 	    OID_AUTO, "cpu_maxmhz", CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NOFETCH,
385 	    sc, 0, cpufreq_sysctl_maxmhz, "IU", "Maximum CPU frequency");
386 
387 	SYSCTL_ADD_INT(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx6),
388 	    OID_AUTO, "cpu_maxmhz_hw", CTLFLAG_RD, &sc->cpu_maxmhz_hw, 0,
389 	    "Maximum CPU frequency allowed by hardware");
390 
391 	SYSCTL_ADD_INT(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx6),
392 	    OID_AUTO, "cpu_overclock_enable", CTLFLAG_RWTUN,
393 	    &sc->cpu_overclock_enable, 0,
394 	    "Allow setting CPU frequency higher than cpu_maxmhz_hw");
395 
396 	/*
397 	 * XXX 24mhz shouldn't be hard-coded, should get this from imx6_ccm
398 	 * (even though in the real world it will always be 24mhz).  Oh wait a
399 	 * sec, I never wrote imx6_ccm.
400 	 */
401 	sc->refosc_mhz = 24;
402 
403 	/*
404 	 * Get the maximum speed this cpu can be set to.  The values in the
405 	 * OCOTP CFG3 register are not documented in the reference manual.
406 	 * The following info was in an archived email found via web search:
407 	 *   - 2b'11: 1200000000Hz;
408 	 *   - 2b'10: 996000000Hz;
409 	 *   - 2b'01: 852000000Hz; -- i.MX6Q Only, exclusive with 996MHz.
410 	 *   - 2b'00: 792000000Hz;
411 	 * The default hardware max speed can be overridden by a tunable.
412 	 */
413 	cfg3speed = (fsl_ocotp_read_4(FSL_OCOTP_CFG3) &
414 	    FSL_OCOTP_CFG3_SPEED_MASK) >> FSL_OCOTP_CFG3_SPEED_SHIFT;
415 	sc->cpu_maxmhz_hw = imx6_ocotp_mhz_tab[cfg3speed];
416 	sc->cpu_maxmhz = sc->cpu_maxmhz_hw;
417 
418 	TUNABLE_INT_FETCH("hw.imx6.cpu_minmhz", &sc->cpu_minmhz);
419 	op = cpufreq_nearest_oppt(sc, sc->cpu_minmhz);
420 	sc->cpu_minmhz = op->mhz;
421 	sc->cpu_minmv = op->mv;
422 
423 	TUNABLE_INT_FETCH("hw.imx6.cpu_maxmhz", &sc->cpu_maxmhz);
424 	op = cpufreq_nearest_oppt(sc, sc->cpu_maxmhz);
425 	sc->cpu_maxmhz = op->mhz;
426 	sc->cpu_maxmv = op->mv;
427 
428 	/*
429 	 * Set the CPU to maximum speed.
430 	 *
431 	 * We won't have thermal throttling until interrupts are enabled, but we
432 	 * want to run at full speed through all the device init stuff.  This
433 	 * basically assumes that a single core can't overheat before interrupts
434 	 * are enabled; empirical testing shows that to be a safe assumption.
435 	 */
436 	cpufreq_set_clock(sc, op);
437 }
438 
439 static inline uint32_t
440 temp_from_count(struct imx6_anatop_softc *sc, uint32_t count)
441 {
442 
443 	return (((sc->temp_high_val - (count - sc->temp_high_cnt) *
444 	    (sc->temp_high_val - 250) /
445 	    (sc->temp_room_cnt - sc->temp_high_cnt))));
446 }
447 
448 static inline uint32_t
449 temp_to_count(struct imx6_anatop_softc *sc, uint32_t temp)
450 {
451 
452 	return ((sc->temp_room_cnt - sc->temp_high_cnt) *
453 	    (sc->temp_high_val - temp) / (sc->temp_high_val - 250) +
454 	    sc->temp_high_cnt);
455 }
456 
457 static void
458 temp_update_count(struct imx6_anatop_softc *sc)
459 {
460 	uint32_t val;
461 
462 	val = imx6_anatop_read_4(IMX6_ANALOG_TEMPMON_TEMPSENSE0);
463 	if (!(val & IMX6_ANALOG_TEMPMON_TEMPSENSE0_VALID))
464 		return;
465 	sc->temp_last_cnt =
466 	    (val & IMX6_ANALOG_TEMPMON_TEMPSENSE0_TEMP_CNT_MASK) >>
467 	    IMX6_ANALOG_TEMPMON_TEMPSENSE0_TEMP_CNT_SHIFT;
468 }
469 
470 static int
471 temp_sysctl_handler(SYSCTL_HANDLER_ARGS)
472 {
473 	struct imx6_anatop_softc *sc = arg1;
474 	uint32_t t;
475 
476 	temp_update_count(sc);
477 
478 	t = temp_from_count(sc, sc->temp_last_cnt) + TZ_ZEROC;
479 
480 	return (sysctl_handle_int(oidp, &t, 0, req));
481 }
482 
483 static int
484 temp_throttle_sysctl_handler(SYSCTL_HANDLER_ARGS)
485 {
486 	struct imx6_anatop_softc *sc = arg1;
487 	int err;
488 	uint32_t temp;
489 
490 	temp = sc->temp_throttle_val + TZ_ZEROC;
491 	err = sysctl_handle_int(oidp, &temp, 0, req);
492 	if (temp < TZ_ZEROC)
493 		return (ERANGE);
494 	temp -= TZ_ZEROC;
495 	if (err != 0 || req->newptr == NULL || temp == sc->temp_throttle_val)
496 		return (err);
497 
498 	/* Value changed, update counts in softc and hardware. */
499 	sc->temp_throttle_val = temp;
500 	sc->temp_throttle_trigger_cnt = temp_to_count(sc, sc->temp_throttle_val);
501 	sc->temp_throttle_reset_cnt = temp_to_count(sc, sc->temp_throttle_val - 100);
502 	imx6_anatop_write_4(IMX6_ANALOG_TEMPMON_TEMPSENSE0_CLR,
503 	    IMX6_ANALOG_TEMPMON_TEMPSENSE0_ALARM_MASK);
504 	imx6_anatop_write_4(IMX6_ANALOG_TEMPMON_TEMPSENSE0_SET,
505 	    (sc->temp_throttle_trigger_cnt <<
506 	     IMX6_ANALOG_TEMPMON_TEMPSENSE0_ALARM_SHIFT));
507 	return (err);
508 }
509 
510 static void
511 tempmon_gofast(struct imx6_anatop_softc *sc)
512 {
513 
514 	if (sc->cpu_curmhz < sc->cpu_maxmhz) {
515 		cpufreq_set_clock(sc, cpufreq_nearest_oppt(sc, sc->cpu_maxmhz));
516 	}
517 }
518 
519 static void
520 tempmon_goslow(struct imx6_anatop_softc *sc)
521 {
522 
523 	if (sc->cpu_curmhz > sc->cpu_minmhz) {
524 		cpufreq_set_clock(sc, cpufreq_nearest_oppt(sc, sc->cpu_minmhz));
525 	}
526 }
527 
528 static int
529 tempmon_intr(void *arg)
530 {
531 	struct imx6_anatop_softc *sc = arg;
532 
533 	/*
534 	 * XXX Note that this code doesn't currently run (for some mysterious
535 	 * reason we just never get an interrupt), so the real monitoring is
536 	 * done by tempmon_throttle_check().
537 	 */
538 	tempmon_goslow(sc);
539 	/* XXX Schedule callout to speed back up eventually. */
540 	return (FILTER_HANDLED);
541 }
542 
543 static void
544 tempmon_throttle_check(void *arg)
545 {
546 	struct imx6_anatop_softc *sc = arg;
547 
548 	/* Lower counts are higher temperatures. */
549 	if (sc->temp_last_cnt < sc->temp_throttle_trigger_cnt)
550 		tempmon_goslow(sc);
551 	else if (sc->temp_last_cnt > (sc->temp_throttle_reset_cnt))
552 		tempmon_gofast(sc);
553 
554 	callout_reset_sbt(&sc->temp_throttle_callout, sc->temp_throttle_delay,
555 		0, tempmon_throttle_check, sc, 0);
556 
557 }
558 
559 static void
560 initialize_tempmon(struct imx6_anatop_softc *sc)
561 {
562 	uint32_t cal;
563 
564 	/*
565 	 * Fetch calibration data: a sensor count at room temperature (25C),
566 	 * a sensor count at a high temperature, and that temperature
567 	 */
568 	cal = fsl_ocotp_read_4(FSL_OCOTP_ANA1);
569 	sc->temp_room_cnt = (cal & 0xFFF00000) >> 20;
570 	sc->temp_high_cnt = (cal & 0x000FFF00) >> 8;
571 	sc->temp_high_val = (cal & 0x000000FF) * 10;
572 
573 	/*
574 	 * Throttle to a lower cpu freq at 10C below the "hot" temperature, and
575 	 * reset back to max cpu freq at 5C below the trigger.
576 	 */
577 	sc->temp_throttle_val = sc->temp_high_val - 100;
578 	sc->temp_throttle_trigger_cnt =
579 	    temp_to_count(sc, sc->temp_throttle_val);
580 	sc->temp_throttle_reset_cnt =
581 	    temp_to_count(sc, sc->temp_throttle_val - 50);
582 
583 	/*
584 	 * Set the sensor to sample automatically at 16Hz (32.768KHz/0x800), set
585 	 * the throttle count, and begin making measurements.
586 	 */
587 	imx6_anatop_write_4(IMX6_ANALOG_TEMPMON_TEMPSENSE1, 0x0800);
588 	imx6_anatop_write_4(IMX6_ANALOG_TEMPMON_TEMPSENSE0,
589 	    (sc->temp_throttle_trigger_cnt <<
590 	    IMX6_ANALOG_TEMPMON_TEMPSENSE0_ALARM_SHIFT) |
591 	    IMX6_ANALOG_TEMPMON_TEMPSENSE0_MEASURE);
592 
593 	/*
594 	 * XXX Note that the alarm-interrupt feature isn't working yet, so
595 	 * we'll use a callout handler to check at 10Hz.  Make sure we have an
596 	 * initial temperature reading before starting up the callouts so we
597 	 * don't get a bogus reading of zero.
598 	 */
599 	while (sc->temp_last_cnt == 0)
600 		temp_update_count(sc);
601 	sc->temp_throttle_delay = 100 * SBT_1MS;
602 	callout_init(&sc->temp_throttle_callout, 0);
603 	callout_reset_sbt(&sc->temp_throttle_callout, sc->temp_throttle_delay,
604 	    0, tempmon_throttle_check, sc, 0);
605 
606 	SYSCTL_ADD_PROC(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx6),
607 	    OID_AUTO, "temperature", CTLTYPE_INT | CTLFLAG_RD, sc, 0,
608 	    temp_sysctl_handler, "IK", "Current die temperature");
609 	SYSCTL_ADD_PROC(NULL, SYSCTL_STATIC_CHILDREN(_hw_imx6),
610 	    OID_AUTO, "throttle_temperature", CTLTYPE_INT | CTLFLAG_RW, sc,
611 	    0, temp_throttle_sysctl_handler, "IK",
612 	    "Throttle CPU when exceeding this temperature");
613 }
614 
615 static void
616 intr_setup(void *arg)
617 {
618 	struct imx6_anatop_softc *sc;
619 
620 	sc = arg;
621 	bus_setup_intr(sc->dev, sc->res[IRQRES], INTR_TYPE_MISC | INTR_MPSAFE,
622 	    tempmon_intr, NULL, sc, &sc->temp_intrhand);
623 	config_intrhook_disestablish(&sc->intr_setup_hook);
624 }
625 
626 static void
627 imx6_anatop_new_pass(device_t dev)
628 {
629 	struct imx6_anatop_softc *sc;
630 	const int cpu_init_pass = BUS_PASS_CPU + BUS_PASS_ORDER_MIDDLE;
631 
632 	/*
633 	 * We attach during BUS_PASS_BUS (because some day we will be a
634 	 * simplebus that has regulator devices as children), but some of our
635 	 * init work cannot be done until BUS_PASS_CPU (we rely on other devices
636 	 * that attach on the CPU pass).
637 	 */
638 	sc = device_get_softc(dev);
639 	if (!sc->cpu_init_done && bus_current_pass >= cpu_init_pass) {
640 		sc->cpu_init_done = true;
641 		cpufreq_initialize(sc);
642 		initialize_tempmon(sc);
643 		if (bootverbose) {
644 			device_printf(sc->dev, "CPU %uMHz @ %umV\n",
645 			    sc->cpu_curmhz, sc->cpu_curmv);
646 		}
647 	}
648 	bus_generic_new_pass(dev);
649 }
650 
651 static int
652 imx6_anatop_detach(device_t dev)
653 {
654 
655 	/* This device can never detach. */
656 	return (EBUSY);
657 }
658 
659 static int
660 imx6_anatop_attach(device_t dev)
661 {
662 	struct imx6_anatop_softc *sc;
663 	int err;
664 
665 	sc = device_get_softc(dev);
666 	sc->dev = dev;
667 
668 	/* Allocate bus_space resources. */
669 	if (bus_alloc_resources(dev, imx6_anatop_spec, sc->res)) {
670 		device_printf(dev, "Cannot allocate resources\n");
671 		err = ENXIO;
672 		goto out;
673 	}
674 
675 	sc->intr_setup_hook.ich_func = intr_setup;
676 	sc->intr_setup_hook.ich_arg = sc;
677 	config_intrhook_establish(&sc->intr_setup_hook);
678 
679 	SYSCTL_ADD_UINT(device_get_sysctl_ctx(sc->dev),
680 	    SYSCTL_CHILDREN(device_get_sysctl_tree(sc->dev)),
681 	    OID_AUTO, "cpu_voltage", CTLFLAG_RD,
682 	    &sc->cpu_curmv, 0, "Current CPU voltage in millivolts");
683 
684 	imx6_anatop_sc = sc;
685 
686 	/*
687 	 * Other code seen on the net sets this SELFBIASOFF flag around the same
688 	 * time the temperature sensor is set up, although it's unclear how the
689 	 * two are related (if at all).
690 	 */
691 	imx6_anatop_write_4(IMX6_ANALOG_PMU_MISC0_SET,
692 	    IMX6_ANALOG_PMU_MISC0_SELFBIASOFF);
693 
694 	/*
695 	 * Some day, when we're ready to deal with the actual anatop regulators
696 	 * that are described in fdt data as children of this "bus", this would
697 	 * be the place to invoke a simplebus helper routine to instantiate the
698 	 * children from the fdt data.
699 	 */
700 
701 	err = 0;
702 
703 out:
704 
705 	if (err != 0) {
706 		bus_release_resources(dev, imx6_anatop_spec, sc->res);
707 	}
708 
709 	return (err);
710 }
711 
712 uint32_t
713 pll4_configure_output(uint32_t mfi, uint32_t mfn, uint32_t mfd)
714 {
715 	int reg;
716 
717 	/*
718 	 * Audio PLL (PLL4).
719 	 * PLL output frequency = Fref * (DIV_SELECT + NUM/DENOM)
720 	 */
721 
722 	reg = (IMX6_ANALOG_CCM_PLL_AUDIO_ENABLE);
723 	reg &= ~(IMX6_ANALOG_CCM_PLL_AUDIO_DIV_SELECT_MASK << \
724 		IMX6_ANALOG_CCM_PLL_AUDIO_DIV_SELECT_SHIFT);
725 	reg |= (mfi << IMX6_ANALOG_CCM_PLL_AUDIO_DIV_SELECT_SHIFT);
726 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_AUDIO, reg);
727 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_AUDIO_NUM, mfn);
728 	imx6_anatop_write_4(IMX6_ANALOG_CCM_PLL_AUDIO_DENOM, mfd);
729 
730 	return (0);
731 }
732 
733 static int
734 imx6_anatop_probe(device_t dev)
735 {
736 
737 	if (!ofw_bus_status_okay(dev))
738 		return (ENXIO);
739 
740 	if (ofw_bus_is_compatible(dev, "fsl,imx6q-anatop") == 0)
741 		return (ENXIO);
742 
743 	device_set_desc(dev, "Freescale i.MX6 Analog PLLs and Power");
744 
745 	return (BUS_PROBE_DEFAULT);
746 }
747 
748 uint32_t
749 imx6_get_cpu_clock()
750 {
751 	uint32_t div;
752 
753 	div = imx6_anatop_read_4(IMX6_ANALOG_CCM_PLL_ARM) &
754 	    IMX6_ANALOG_CCM_PLL_ARM_DIV_MASK;
755 	return (cpufreq_mhz_from_div(imx6_anatop_sc, div));
756 }
757 
758 static device_method_t imx6_anatop_methods[] = {
759 	/* Device interface */
760 	DEVMETHOD(device_probe,  imx6_anatop_probe),
761 	DEVMETHOD(device_attach, imx6_anatop_attach),
762 	DEVMETHOD(device_detach, imx6_anatop_detach),
763 
764 	/* Bus interface */
765 	DEVMETHOD(bus_new_pass,  imx6_anatop_new_pass),
766 
767 	DEVMETHOD_END
768 };
769 
770 static driver_t imx6_anatop_driver = {
771 	"imx6_anatop",
772 	imx6_anatop_methods,
773 	sizeof(struct imx6_anatop_softc)
774 };
775 
776 static devclass_t imx6_anatop_devclass;
777 
778 EARLY_DRIVER_MODULE(imx6_anatop, simplebus, imx6_anatop_driver,
779     imx6_anatop_devclass, 0, 0, BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
780 EARLY_DRIVER_MODULE(imx6_anatop, ofwbus, imx6_anatop_driver,
781     imx6_anatop_devclass, 0, 0, BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
782 
783